Disc flutter compensating suspension

Abstract

A suspension is provided, which has proximal and distal ends and a longitudinal axis extending from the proximal end toward the distal end. A rotating hinge rotates the distal end about the longitudinal axis in response to vertical motion of the distal end relative to the proximal end. In one example, the suspension includes a preformed twist deformation, which rotates the distal end about the longitudinal axis relative to the proximal end axis in a direction opposite to rotation by the rotating hinge, in response to the vertical motion.

1 . A suspension comprising:
 proximal and distal ends;   a longitudinal axis extending from the proximal end toward the distal end;   a rotating hinge between the proximal and distal ends, which rotates the distal end about the longitudinal axis in response to vertical motion of the distal end relative to the proximal end; and   a preformed twist deformation, which rotates the distal end about the longitudinal axis relative to the proximal end axis in a direction opposite to rotation by the rotating hinge, in response to the vertical motion.   
     
     
         2 . The suspension of  claim 1  wherein the rotating hinge is free of any twist deformation about the longitudinal axis. 
     
     
         3 . The suspension of  claim 1  wherein preformed twist deformation is confined to an area between and not-overlapping the rotating hinge and the distal end. 
     
     
         4 . The suspension of  claim 1  wherein:
 the suspension comprises a proximal mounting section and a load beam; and   the rotating hinge comprises first and second laterally offset beams extending between the proximal mounting section and the load beam and comprising top and bottom surfaces, wherein the top and bottom surfaces of the first beam are offset from the top and bottom surfaces, respectively, of the second beam in a direction normal to the surfaces.   
     
     
         5 . The suspension of  claim 4  and further comprising:
 a shim positioned between the proximal mounting section and the load beam such that the shim offsets the top and bottom surfaces of the first beam from the top and bottom surfaces, respectively, of the second beam in a direction normal to the surfaces.   
     
     
         6 . The suspension of  claim 1  wherein:
 the suspension comprises a base and a load beam; and   the rotating hinge structure statically tilts the load beam relative to the base about the longitudinal axis.   
     
     
         7 . The suspension of  claim 1  wherein the preformed twist deformation is confined to an area on the suspension that is entirely distal to the rotating hinge. 
     
     
         8 . A device comprising:
 a first section;   a second section, at least one of the first and second sections having a recessed portion and a laterally-offset non-recessed portion; and   a hinge structure adjacent the recessed and non-recessed portions and comprising first and second laterally offset beams extending between the first and second sections and having top and bottom surfaces, wherein the first beam extends from the non-recessed portion and the second beam extends from the recessed portion such that the top and bottom surfaces of the first beam are vertically offset from the top and bottom surfaces, respectively, of the second beam in a direction normal to the surfaces.   
     
     
         9 . The device of  claim 8  wherein:
 the first section has first and second opposite surfaces, the first surface comprising the recessed portion and the non-recessed portion adjacent the hinge structure:   
     
     
         10 . The device of  claim 9  wherein:
 the first beam is attached to one surface of the second section and the second beam is attached to an opposite surface of the second section.   
     
     
         11 . The device of  claim 9  wherein the hinge structure comprises material that extends from the first and second beams and overlaps at least a portion of the first section and comprises at least one strut extending from the material on the non-recessed portion to the material on the recessed portion. 
     
     
         12 . The device of  claim 9  wherein the first section further comprises a further recessed portion on the second surface, opposite the recessed portion on the first surface. 
     
     
         13 . The device of  claim 9  wherein the second section comprises a recessed portion and a non-recessed portion adjacent the hinge structure, and wherein the first beam is attached to the non-recessed portion of the second section and the second beam is attached to the recessed portion of the second section. 
     
     
         14 . The device of  claim 13  wherein the first section and the second section are formed of the same thickness of material and the recessed portions in the first and second sections have the same step depth relative to the non-recessed portions. 
     
     
         15 . The device of  claim 8  wherein the first beam is attached to a first surface of the first section and the second beam is attached to a second, opposite surface of the first section. 
     
     
         16 . The device of  claim 8  wherein the device comprises a suspension, the first section comprises a base plate and the second section comprises a load beam.